Frequently Asked Questions
| Question/Problem | Answer |
|---|---|
When trying to build a Ledger embedded app via the make command on some apps, this error could appear fatal error: 'zxmacros.h' file not found (or any other .h file). | Run git submodule update --init on the repo’s root or git clone https://github.com/application.git" --recurse-submodules. |
| What is the maximum size of a message that can be sent in a single APDU? | The length of the data part is 255 bytes and the whole message sent in a single APDU is 260 bytes with the blocks cla, ins, p1, p2 and one extra byte that encodes the length of the data that follows. |
| The Ledger team can not fork a repo which is already a fork on LedgerHQ (e.g. ledger-panacea is a clone of ledger-cosmos but LedgerHQ has already a fork of ledger-cosmos). | This is a limitation of GitHub and the only solution for this is to break the link between the repository and the upstream one. This is done like in this tutorial (opens in a new tab). |
| Can I freely choose the CLA in my embedded app as long as it is one byte or is there eanything I need to be aware of? | Apart from not using a few CLAs that are reserved for the SDK, OS, etc, developers are free to choose. For example, 0xB0 is for SDK. |
| How can I load an app without Ledger Live on my ledger nano S or S+? | Here are the links to the documentation. |
When I build the application, I have this error message: No targets specified and no makefile found. | You need to go down one level in the repo to the app subfolder and then run the make command. You must have launched your ledger-app-builder before. |
I'm getting the error message Ledger device: CLA_NOT_SUPPORTED. | Many reasons could occur this error: the embedded app does not support the functionality you are implementing yet, you opened the wrong embedded app, or the CLA byte is not correctly set. |
| How do I verify that my product is genuine (in CLI)? | You can check it by connecting your hardware wallet and executing the following commands in this documentation (opens in a new tab). |
| Could we submit an Embedded App for a developer release when the blockchain is still on testnet? | Yes, it's possible. |
GitHub actions are suddenly failing because the code rely on brew, what should I do? | You have to remove brew from the codebase. brew has been removed from GitHub base ubuntu images. This link (opens in a new tab) is the description of the latest ubuntu image. It points to the issue (opens in a new tab) where brew has been removed. |
